Schizophrenia is a chronic, severe, and disabling brain disease. Approximately 1 percent of the population develops schizophrenia during their lifetime"more than 2 million Americans suffer from the illness in a given year. Although schizophrenia affects men and women with equal frequency, the disorder often appears earlier in men, usually in the late teens or early twenties, than in women, who are generally affected in the twenties to early thirties. People with schizophrenia often suffer terrifying symptoms such as hearing internal voices not heard by others, or believing that other people are reading their minds, controlling their thoughts, or plotting to harm them. These symptoms may leave them fearful and withdrawn. Their speech and behavior can be so disorganized that they may be incomprehensible or frightening to others. Available treatments can relieve many symptoms, but most people with schizohphrenia continue to suffer some symptoms throughout their lives; it has been estimated that no more than one in five individuals recovers completely.

This is a time of hope for people with schizophrenia and their families. Research is gradually leading to new and safer medications and unraveling the complex causes of the disease. Scientists are using many approaches from the study of molecular genetics to the study of populations to learn about schizophrenia. Methods of imaging the brain's structure and function hold the promise of new insights into the disorder.

Schizophrenia as an Illness

Schizophrenia is found all over the world. The severity of the symptoms and long-lasting, chronic pattern of schizophrenia often cause a high degree of disability. Medications and other treatments for schizophrenia, when used regularly and as prescribed, can help reduce and control the distressing symptoms of the illness. However, some people are not greatly helped by available treatments or may prematurely discontinue treatment because of unpleasant side effects or other reasons. Even when treatment is effective, persisting consequences of the illness"lost opportunities, stigma, residual symptoms, and medication side effects"may be very troubling.

The first signs of schizophrenia often appear as confusing, or even shocking, changes in behavior. Coping with the symptoms of schizophrenia can be especially difficult for family members who remember how involved or vivacious a person was before they became ill. The sudden onset of severe psychotic symptoms is referred to as an "acute phase of schizophrenia. "Psychosis, a common condition in schizophrenia, is a state of mental impairment marked by hallucinations, which are disturbances of sensory perception, and/or delusions, which are false yet strongly held personal beliefs that result from an inability to separate real from unreal experiences. Less obvious symptoms, such as social isolation or withdrawal, or unusual speech, thinking, or behavior, may precede, be seen along with, or follow the psychotic symptoms. Some people have only one such psychotic episode; others have many episodes during a lifetime, but lead relatively normal lives during the interim periods. However, the individual with "chronic schizophrenia, or a continuous or recurring pattern of illness, often does not fully recover normal functioning and typically requires long-term treatment, generally including medication, to control the symptoms.

Making a Diagnosis

It is important to rule out other illnesses, as sometimes people suffer severe mental symptoms or even psychosis due to undetected underlying medical conditions. For this reason, a medical history should be taken and a physical examination and laboratory tests should be done to rule out other possible causes of the symptoms before concluding that a person has schizophrenia. In addition, since commonly abused drugs may cause symptoms resembling schizophrenia, blood or urine samples from the person can be tested at hospitals or physicians offices for the presence of these drugs.

At times, it is difficult to tell one mental disorder from another. For instance, some people with symptoms of schizophrenia exhibit prolonged extremes of elated or depressed mood, and it is important to determine whether such a patient has schizophrenia or actually has a manic-depressive (or bipolar) disorder or major depressive disorder. Persons whose symptoms cannot be clearly categorized are sometimes diagnosed as having a "schizoaffective disorder."

Can Children Have Schizophrenia?

Children over the age of five can develop schizophrenia, but it is very rare before adolescence. Although some people who later develop schizophrenia may have seemed different from other children at an early age, the psychotic symptoms of schizophrenia"hallucinations and delusions"are extremely uncommon before adolescence.

The World of People

With Schizophrenia

Distorted Perceptions of Reality

People with schizophrenia may have perceptions of reality that are strikingly different from the reality seen and shared by others around them. Living in a world distorted by hallucinations and delusions, individuals with schizophrenia may feel frightened, anxious, and confused.

In part because of the unusual realities they experience, people with schizophrenia may behave very differently at various times. Sometimes they may seem distant, detached, or preoccupied and may even sit as rigidly as a stone, not moving for hours or uttering a sound. Other times they may move about constantly"always occupied, appearing wide-awake, vigilant, and alert.

Hallucinations and Illusions

Hallucinations and illusions are disturbances of perception that are common in people suffering from schizophrenia. Hallucinations are perceptions that occur without connection to an appropriate source. Although hallucinations can occur in any sensory form"auditory (sound), visual (sight), tactile (touch), gustatory (taste), and olfactory (smell)"hearing voices that other people do not hear is the most common type of hallucination in schizophrenia. Voices may describe the patient's activities, carry on a conversation, warn of impending dangers, or even issue orders to the individual. Illusions, on the other hand, occur when a sensory stimulus is present but is incorrectly interpreted by the individual.

Delusions

Delusions are false personal beliefs that are not subject to reason or contradictory evidence and are not explained by a person's usual cultural concepts. Delusions may take on different themes. For example, patients suffering from paranoid-type symptoms"roughly one-third of people with schizophrenia"often have delusions of persecution, or false and irrational beliefs that they are being cheated, harassed, poisoned, or conspired against. These patients may believe that they, or a member of the family or someone close to them, are the focus of this persecution. In addition, delusions of grandeur, in which a person may believe he or she is a famous or important figure, may occur in schizophrenia. Sometimes the delusions experienced by people with schizophrenia are quite bizarre; for instance, believing that a neighbor is controlling their behavior with magnetic waves; that people on television are directing special messages to them; or that their thoughts are being broadcast aloud to others.

Disordered Thinking

Schizophrenia often affects a person's ability to "think straight." Thoughts may come and go rapidly; the person may not be able to concentrate on one thought for very long and may be easily distracted, unable to focus attention.

People with schizophrenia may not be able to sort out what is relevant and what is not relevant to a situation. The person may be unable to connect thoughts into logical sequences, with thoughts becoming disorganized and fragmented. This lack of logical continuity of thought, termed "thought disorder, can make conversation very difficult and may contribute to social isolation. If people cannot make sense of what an individual is saying, they are likely to become uncomfortable and tend to leave that person alone.

Emotional Expression

People with schizophrenia often show "blunted or "flat affect. This refers to a severe reduction in emotional expressiveness. A person with schizophrenia may not show the signs of normal emotion, perhaps may speak in a monotonous voice, have diminished facial expressions, and appear extremely apathetic. The person may withdraw socially, avoiding contact with others; and when forced to interact, he or she may have nothing to say, reflecting "impoverished thought." Motivation can be greatly decreased, as can interest in or enjoyment of life. In some severe cases, a person can spend entire days doing nothing at all, even neglecting basic hygiene. These problems with emotional expression and motivation, which may be extremely troubling to family members and friends, are symptoms of schizophrenia"not character flaws or personal weaknesses.

Normal Versus Abnormal

At times, normal individuals may feel, think, or act in ways that resemble schizophrenia. Normal people may sometimes be unable to "think straight." They may become extremely anxious, for example, when speaking in front of groups and may feel confused, be unable to pull their thoughts together, and forget what they had intended to say. This is not schizophrenia. At the same time, people with schizophrenia do not always act abnormally. Indeed, some people with the illness can appear completely normal and be perfectly responsible, even while they experience hallucinations or delusions. An individual's behavior may change over time, becoming bizarre if medication is stopped and returning closer to normal when receiving appropriate treatment.

Are People With Schizophrenia Likely To Be Violent?

News and entertainment media tend to link mental illness and criminal violence; however, studies indicate that except for those persons with a record of criminal violence before becoming ill, and those with substance abuse or alcohol problems, people with Schizophrenia are not especially prone to violence.

Most individuals with schizophrenia are not violent; more typically, they are withdrawn and prefer to be left alone. Most violent crimes are not committed by persons with schizophrenia, and most persons with schizophrenia do not commit violent crimes.

Substance abuse significantly raises the rate of violence in people with schizophrenia but also in people who do not have any mental illness. People with paranoid and psychotic symptoms, which can become worse if medications are discontinued, may also be at higher risk for violent behavior. When violence does occur, it is most frequently targeted at family members and friends, and more often takes place at home.

Substance Abuse

Substance abuse is a common concern of the family and friends of people with schizophrenia. Since some people who abuse drugs may show symptoms similar to those of schizophrenia, people with schizophrenia may be mistaken for people "high on drugs." while most researchers do not believe that substance abuse causes schizophrenia, people who have schizophrenia often abuse alcohol and/or drugs, and may have particularly bad reactions to certain drugs. Substance abuse can reduce the effectiveness of treatment for schizophrenia. Stimulants (such as amphetamines or cocaine) may cause major problems for patients with schizophrenia, as may PCP or marijuana. In fact, some people experience a worsening of their schizophrenic symptoms when they are taking such drugs. Substance abuse also reduces the likelihood that patients will follow the treatment plans recommended by their doctors.

Schizophrenia and Nicotine

The most common form of substance use disorder in people with schizophrenia is nicotine dependence due to smoking. While the prevalence of smoking in the U.S. population is about 25 to 30 percent, the prevalence among people with schizophrenia is approximately three times as high. Research has shown that the relationship between smoking and schizophrenia is complex. Although people with schizophrenia may smoke to self medicate their symptoms, smoking interferes with the response to antipsychotic drugs. Several studies have found that schizophrenia patients who smoke need higher doses of antipsychotic medication. Quitting smoking may be especially difficult for people with schizophrenia, because the symptoms of nicotine withdrawal may cause a temporary worsening of schizophrenia symptoms. However, smoking cessation strategies that include nicotine replacement methods may be effective. Doctors should carefully monitor medication dosage and response when patients with schizophrenia either start or stop smoking.

What About Suicide?

Suicide is a serious danger in people who have schizophrenia. If an individual tries to commit suicide or threatens to do so, professional help should be sought immediately. People with schizophrenia have a higher rate of suicide than the general population. Approximately 10 percent of people with schizophrenia (especially younger adult males) commit suicide. Unfortunately, the prediction of suicide in people with schizophrenia can be especially difficult.

WHAT CAUSES SCHIZOPHRENIA?

There is no known single cause of schizophrenia. Many diseases, such as heart disease, result from

an interplay of genetic, environmental, and behavioral factors; and this may be the case for schizophrenia as well. Scientists do not yet understand all of the factors necessary to produce schizophrenia, but all the tools of modern biomedical research are being used to search for genes, critical moments in brain development, and environmental factors that may lead to the illness.

Is Schizophrenia Inherited?

It has long been known that schizophrenia runs in families. People who have a close relative with schizophrenia are more likely to develop the disorder than are people who have no relatives with the illness. For example, a monozygotic (identical) twin of a person with schizophrenia has the highest risk"40 to 50 percent"of developing the illness. A child whose parent has schizophrenia has about a 10 percent chance. By comparison, the risk of schizophrenia in the general population is about 1 percent.

Scientists are studying genetic factors in schizophrenia. It appears likely that multiple genes are involved in creating a predisposition to develop the disorder. In addition, factors such as prenatal difficulties like intrauterine starvation or viral infections, perinatal complications, and various nonspecific stressors, seem to influence the development of schizophrenia. However, it is not yet understood how the genetic predisposition is transmitted, and it cannot yet be accurately predicted whether a given person will or will not develop the disorder.

Several regions of the human genome are being investigated to identify genes that may confer susceptibility for schizophrenia. The strongest evidence to date leads to chromosomes 13 and 6 but remains unconfirmed. Identification of specific genes involved in the development of schizophrenia will provide important clues into what goes wrong in the brain to produce and sustain the illness and will guide the development of new and better treatments. To learn more about the genetic basis for schizophrenia, the NIMH has established a Schizophrenia Genetics Initiative that is gathering data from a large number of families of people with the illness.

Is Schizophrenia Associated With a Chemical Defect in the Brain?

Basic knowledge about brain chemistry and its link to schizophrenia is expanding rapidly. Neurotransmitters, substances that allow communication between nerve cells, have long been thought to be involved in the development of schizophrenia. It is likely, although not yet certain, that the disorder is associated with some imbalance of the complex, interrelated chemical systems of the brain, perhaps involving the neurotransmitters dopamine and glutamate. This area of research is promising.

Is Schizophrenia Caused by a Physical Abnormality in the Brain?

There have been dramatic advances in

neuroimaging technology that permit scientists to study brain structure and function in living individuals. Many studies of people with schizophrenia have found abnormalities in brain structure (for example, enlargement of the fluid-filled cavities, called the ventricles, in the interior of the brain, and decreased size of certain brain regions) or function (for example, decreased metabolic activity in certain brain regions). It should be emphasized that these abnormalities are quite subtle and are not characteristic of all people with schizophrenia, nor do they occur only in individuals with this illness. Microscopic studies of brain tissue after death have also shown small changes in distribution or number of brain cells in people with schizophrenia. It appears that many (but probably not all) of these changes are present before an individual becomes ill, and schizophrenia may be, in part, a disorder in development of the brain.

Developmental neurobiologists funded by the National Institute of Mental Health (NIMH) have found that schizophrenia may be a developmental disorder resulting when neurons form inappropriate connections during fetal development. These errors may lie dormant until puberty, when changes in the brain that occur normally during this critical stage of maturation interact adversely with the faulty connections. This research has spurred efforts to identify prenatal factors that may have some bearing on the apparent developmental abnormality.

In other studies, investigators using brain-imaging techniques have found evidence of early biochemical changes that may precede the onset of disease symptoms, prompting examination of the neural circuits that are most likely to be involved in producing those symptoms. Scientists working at the molecular level, meanwhile, are exploring the genetic basis for abnormalities in brain development and in the neurotransmitter systems regulating brain function.